Spark-plug.



R, CHAM PUN.

SPARK PLUG.

' APPLICATION FILED JUNE'ZO, 1917.

Patented July 30, 1918.

WITNESSES 1 m I I 4/ t ATTO R N EY UNITED STATES PATENT OFFICE.

RAYMOND CHAMPLILLOF BREMERTON, WASHINGTON, ASSIGNOR. ONE-FOURTH TO HERMAN A. TODD AND ONE-FOURTH T0 RICHARD G. COOK, BOTH 0F BREMERTON,

WASHINGTON.

SPARK-PLUG.

Specification of Letters Patent.

Patented July so, 191s.

Application 'filed June 20. 1917. Serial No. 175,918.

To all whom it may concern:

Be it known that I, RAYMOND CHAMPLIN, a citizen of the United States, residing at Bremerton, in the county of Kitsap and State of Washington. have invented new and useful Improvements in Spark-Plugs, of which the following is a specification.

This invention relates to improvements in ignition devices for internal combustion engines, referring particularly to an improved spark plug. 7 I

In carrying out the invention I propose primarily to provide a spark plug having an electrode which is adapted for automatic movement to maintain the surface in a clean condition by friction against portions of the plug, and to prevent pitting or corrosion of any particular portion of the surface.

I further propose to mount the movable electrode in such a manner that the distance between the electrodes will remain substantially the same.

Another object is to arrange the movable electrode in such position that. the gas in the cylinder will have free access to the spark.

One form of the invention is described in the specification below, set forth in the claims, and delineated in the drawings, in which Figure 1 is a side elevation. of a plug constructed in accordance with the present invention.

Fig. is a transverse section taken on the line 2-Q of Fig. 1.

Fig. 3 is an end view. 7

In the drawings, the numeral lzdesignatcs a spark pl ug having the usual shell 2 provided with a hollow screw threaded cylindrical portion 3 for securing the plug in the spark plug opening of a cylinder. Mounted in the shell 2 in the customary manner the insulating element 4 surrounding the center electrode 5 having the end projecting inwardly for discharge of the spark to an electrode on the shell 2.

In the present embodiment of the invention the center or insulated electrode 5 is"- of the usual type, but it is to be understood that I may when desired cinbody'in its construc tion the. principle here shown as utilized only in the non-insulated electrode. 1

In accordance with the invention the latter elect-rode comprises a ball 7 of conduct lug material and preferably of metal such commonly used for spark plug' electrodes, and is seated against the edgeof an opening 8 in the shell 2 of such diameter as to partly receive the ball 7 but not large enough to permit entrance. To facilitate the construetion of the pla and permit free access of gas to the spar-Ii, the portion of the shell 2 formed with the opening 8 preferably constitutes a projection 8 of one sideof the shell as clearly shown in the drawings. For retaining the ball in position means are provided here shown as angularly disposed pins 9 secured in bores in the shell. adjacent the opening 8 and extending suflieient-ly clo'se' to the ball 7 to prevent bodily movement oi any appreciable degree, but adapted to permit rotation of the ball 7 under the in ilucnce of vibration such as that resulting from the operation of the engine. By this rotation in contact with the preferably sharp edge of the opening 8, the hall 7 is maintained in the clean condition most favorable for passage of the spark; and the continually changingpoint of reception-of the spark prevents pitting or corrosion and the consequent widening of the spark gap between the ball and the center electrode 5.

The latter extends to a propehsparlting distance from the ball, and the terminal portion 10 is preferably bent toward the ball to permit the spark to discharge from the end. It will be evident that when desired a second ball 7 may be mounted in the shell 2 in a manner similar to the single ball shown, and that the two balls may be arranged in proximity and at equal distance from the center electrode 5 so that the corrosive action of the spark will be divided between the two balls.

It is to he understood that I do not limit myself to the particular construction described and shown, noreven to the applicaspherical member in sald opening, andmeans for holding the member in said opencated in said extension on each side of the ing while allowing the some to have rotary opening and loosely engaging the member movement therein. to hold the same in place, an a central eleel0 2. A spark plug comprising a shell having t-rocle having its lower end bent toward the 53 one sicle provided with an extension at its spherical n'lember.

lower end having an opening therein a In testimony whereof I alfix my signature. spherical member in said opening, pins 10- RAYMOND CHAMPL'EN. 

